scholarly journals Isomerization and Dehydroaromatization of R(+)-Limonene Over the Ti-MCM-41 Catalyst: Effect of Temperature, Reaction Time and Catalyst Content on Product Yield

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 508 ◽  
Author(s):  
Monika Retajczyk ◽  
Agnieszka Wróblewska

This work describes research on the isomerization of R(+)-limonene over the Ti-MCM-41 catalyst. The studies showed that the Ti-MCM-41 catalyst is an active catalyst in the isomerization of R(+)-limonene. As a result of the isomerization of this compound, it is possible to obtain α-terpinene, γ-terpinene, terpinolene and p-cymene. Terpinolene is the main product of this process, and p-cymene is formed by the alpha-terpinene, gamma-terpinene and terpinolene dehydrogenation. The aforementioned products are of great practical importance. The most favorable reaction conditions leading to the obtaining of limonene isomerization products is the use of the catalyst in an amount of 15 wt% and the temperature of 160 °C. Depending on whether the desired products are the isomers of limonene (γ-terpinene, α-terpinene and terpinolene) or the product of their dehydroaromatization (β-cymene), it is possible to shorten or extend the reaction time. The method for the isomerization of limonene on the Ti-MCM-41 catalyst makes it possible to obtain a significant yield of both the limonene and p-cymene isomers. Longer reaction time is conducive to obtain larger quantities of other reaction products and less desirable products that constitute impurities (oxidized products and polymeric compounds).

2021 ◽  
Vol 18 ◽  
Author(s):  
Mohammad Nikpassand ◽  
Leila Zare Fekri ◽  
Afshin Pourahmad ◽  
Zeinab Jafarian

Introduction: In this study, the synthesis of azo-linked acridine by the reaction of dimedone and synthesized diazoaryl-(2-amino-5-(phenyl)methanone using Ag2S/RHA-MCM-41nanocomposite is reported. Materials and Methods: The synthesized catalyst was characterized by FT-IR, XRD, and SEM. According to the obtained results, Ag2S/RHA-MCM-41 nanocomposite exhibited high activity in the synthesis of azo-acridine derivatives based on desirable yields and reaction time. Products were prepared in 1.5-2 h and with 88-93% yield. In all the reactions, the catalyst could be easily removed and reused, and its catalytic activity was maintained after five uses and did not decrease significantly. The structures of all newly synthesized products were characterized by spectroscopic spectra (FT-IR, 1H NMR, 13C NMR) and elemental analyses. Results and Discussion: The results of the study showed that ionic liquid [DBU]OAc (entry 8) and MCM-41/Ag2S-RHA nanocomposite (entry 8) possessed better efficiency and shorter time than other reaction conditions. Conclusion: In this study, new azo-linked acridine derivatives were synthesized by the reaction of different azo derivatives and dimedone using MCM-41/Ag2S-RHA nanocomposite, and the reaction products were obtained in 1.5-2 h with an efficiency of 88-93%. The short reaction time and high efficiency of the obtained products indicated the high efficiency of this method. In all the reactions, MCM-41/Ag2S-RHA nanocomposite could be easily removed and reused. Its catalytic activity was maintained in the sample reaction after five runs and did not decrease significantly.


2020 ◽  
Vol 2 (33(60)) ◽  
pp. 34-36
Author(s):  
J. Abdullaev ◽  
S. Nurmanov ◽  
A. Parmonov ◽  
D. Mirkhamitova

Synthesis of 2-methylpropanol-1 from ethylene and ethanol at high pressure was investigated. The process parameters were determined and the effect of temperature and reaction time on the product yield was studied.


Author(s):  
Muhammad Imran Din ◽  
Alizzah Amanat ◽  
Zaib Hussain ◽  
Rida Khalid ◽  
Abdul Rauf

2020 ◽  
Vol 02 (03) ◽  
pp. e128-e132
Author(s):  
Shao-Zheng Guo ◽  
Zhi-Qun Yu ◽  
Wei-Ke Su

AbstractThe development of highly efficient C–C bond formation methods for the synthesis of ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-(dimethylamino)acrylate 1 in continuous flow processes has been described, which is based on the concept of rapid and efficient activation of carboxylic acid. 2,4-Dichloro-5-fluorobenzoic acid is rapidly converted into highly reactive 2,4-dichloro-5-fluorobenzoyl chloride by treating with inexpensive and less-toxic solid bis(trichloromethyl)carbonate. And then it rapidly reacts with ethyl 3-(dimethylamino)acrylate to afford the desired 1. This process can be performed under mild conditions. Compared with the traditional tank reactor process, less raw material consumption, higher product yield, less reaction time, higher operation safety ensured by more the environmentally friendly procedure, and process continuity are achieved in the continuous-flow system.


Teknik ◽  
2013 ◽  
Vol 34 (2) ◽  
pp. 116
Author(s):  
Ardian Dwi Yudhistira ◽  
Istadi Istadi

Biodiesel is one of alternative renewable energy source to substitute diesel fuel. Various biodiesel productionprocesses through transesterification reaction with a variety of catalysts have been developed by previousresearcher. This process still has the disadvantage of a long reaction time, and high energy need. DielectricBarrier Discharge (DBD) plasma electro-catalysis may become a solution to overcome the drawbacks in theconventional transesterification process. This process only needs a short time reaction and low energy process.The purpose of this study was to assess the performance of DBD plasma rector in making biodiesel such as: theeffect of high voltage electric value, electrodes gap, mole ratio of methanol / oil, and reaction time. TheResearch method was using GC-MS (Gas Cromatography-Mass Spectrofotometry) and FTIR (FourierTransform Infrared Spectrofotometry) and then it will be analysed the change of chemical bond betweenreactant and product. So, the reaction mechanism can be predicted. Biodiesel is produced using methanol andpalm oil as reactants and DBD plasma used as reactor in batch system. Then, reactants contacted by highvoltage electric. From the results of this research can be concluded that the reaction mechanism occurs in theprocess is the reaction mechanism of cracking, the higher of electric voltage and the longer of reaction time leadto increasing of product yield. The more of mole ratio of methanol / oil and widening the gap between theelectrodes lead to decreased product yield. From this research, product yield maksimum is 89,8% in the variableof rasio mol metanol/palm oil 3:1, voltage 10 kV, electrode gap 1,5 cm, and reaction time 30 seconds.


2019 ◽  
Vol 16 (33) ◽  
pp. 325-336
Author(s):  
V. N. DOBRYANSKIY ◽  
L. N. RABINSKIY ◽  
O. V. TUSHAVINA

The relevance of the problem stated in this article is that the development of aerospace technology increased the demand for good quality materials. An important issue is ensuring durability in conditions of longterm loads and in conditions of damage development. One of the criteria that ensure the toughness of the material is crack resistance. The aim of the work is to study the interlayer crack resistance (fracture toughness) under loading under conditions of separation and transverse shear, interlayer strength, as well as the effect of temperature on interlayer strength, mechanical tensile properties. A comparison of the values of interlayer crack resistance GIС (separation) and GIIС (shear) and of mechanical tensile properties and interlayer strength of carbon fiber samples is made. The main methods for studying this problem were the short-beam method, the DCB method, the ENF method. The results of the experimental data were compared with modeling the processes of the appearance and development of cracks in the finite element complexes ABAQUS and Ansys based on the VVCT models, cohesive elements. Deviations from the experiment were found and conclusions were drawn that the point of application of the load had to be shifted from the edge of the sample, which will reduce the initial separation and increase the stiffness of the sample. Due to the fact that the cohesion zone model is very sensitive to input parameters, it is necessary to know many parameters and take into account a large number of factors. The practical importance of this work is to show how to use the VCCT model to obtain the critical load of the germination of the first crack. The research technique can be used for further experiments, including simulation further stratification with low inaccuracy.


Author(s):  
Deana Qarizada ◽  
Erfan Mohammadian ◽  
Azil Bahari Alias ◽  
Humapar Azhar Rahimi ◽  
Suriatie Binti Mat Yusuf

Distillation is an essential thermo chemical process; it mainly depends on temperature which affects mostly the product yield and composition. The aim of this research is to investigate the effect of temperature on the characterization of bio-oil liquid fraction derived from palm kernel shell (PKS) bio-oil. The temperatures were 100 °C and 140°C. The higher heating value (HHV) obtained were 28.6MJ/Kg and 31.5MJ/Kg for bio-oil fraction 100°C and 140°C respectively. The GC- MS analysis determined that phenol is the dominant product in bio-oil fractions.


2009 ◽  
Vol 6 (2) ◽  
pp. 399-411 ◽  
Author(s):  
G. S. Jha ◽  
P. Chhabra ◽  
G. Suri ◽  
M. Tyagi ◽  
P. Arora ◽  
...  

Sulfur and chlorine containing bifunctional diols with C-S bond has been prepared starting from chloroepoxy alkane and thioalcohol. The studies of FTIR, TLC, HPLC and NMR have been used to understand the reaction mechanism, as well as for optimization of the reaction parameters. The reaction is highly exothermic and the effect of temperature, rate of addition of reagents and reaction time are important factors affecting the formation of diol. Viscosity studies, HPLC, FTIR, NMR and acid number studies have shown that, these parameters could be used as process control parameters for the synthesis of diol. Refractive index of the synthesized diol is found to be higher than that of the reactants used.


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